I have been on 15 cruises and have brought my own wine every time. I probably have been charged corkage 25% percent of the time.
That being said, I bring wine because I collect and love to drink wine. I have no problem with paying a corkage fee. The cruise line is probably making less profit on the corkage than they do on the wine.
I have found that when they realize that I have brought special wine, they treat it (and me) better. They will decant it. On Celebrity they told me to bring the wine down earlier so they could let it breathe. That's worth the corkage.
I think you are one of the lucky ones: we have always been charged corkage fees: I think on our last cruise they did not charge us one night. I am not complaining, just making a comment. NMNita
First Volendam trip we discovered that we could "Pre-order" wine at a discount (10%) and found that to be a good bargain; we got our beaujolais for $22 or so.
Next trip, not only was the pre-order concept gone, but after the first night, so was the beaujolais. BUT, we discovered that on the Lido deck wine by the bottle was much cheaper than in the dining room, so we did use that for nights we ate in the room.
I must add that every time we brought wine from our room to the dining room we were charged the $15 corking fee (both trips) despite the fact that we were in a deluxe suite. I found that unconscionable, especially when they ran out of "our" wine so early in the trip.